I had the same concern about taking stringers out and warping hull from load of my 220 lb weight inside working on it. If it did warp slightly, it wasn't apparent. My boat has 5 stringers. Looks like they changed the design slightly by 1978. I have a stringer resting on the "keel" as well as the two on either side. Seems like over-kill. I used PL cement to bed them, but it was obvious that they just plunked them down in resin in the factory. I did not bother with the closed cell floatation under the deck as I figured it eventually adds huindreds of lbs to the weight of the boat as it absorbs water. Originally they used open cell foam which was a disasterous water sponge. But even closed cell will do this eventually. If no foam worked for 50 years, it's good enough for me. Chuck knew a thing or two about building boats. I intend to add an access hole in the floor between stringers to open up and suck any residual water out and leave it open in the off season so the black mold can't do it's dirty work below deck. Although I've coated everything underneath with glass, resin and gel coat, I worry about freezing water finding crevices to freeze/expand and break the seal, allowing water back into the stringers.
I had the same concern about taking stringers out and warping hull from load of my 220 lb weight inside working on it. If it did warp slightly, it wasn't apparent. My boat has 5 stringers. Looks like they changed the design slightly by 1978. I have a stringer resting on the "keel" as well as the two on either side. Seems like over-kill. I used PL cement to bed them, but it was obvious that they just plunked them down in resin in the factory. I did not bother with the closed cell floatation under the deck as I figured it eventually adds huindreds of lbs to the weight of the boat as it absorbs water. Originally they used open cell foam which was a disasterous water sponge. But even closed cell will do this eventually. If no foam worked for 50 years, it's good enough for me. Chuck knew a thing or two about building boats. I intend to add an access hole in the floor between stringers to open up and suck any residual water out and leave it open in the off season so the black mold can't do it's dirty work below deck. Although I've coated everything underneath with glass, resin and gel coat, I worry about freezing water finding crevices to freeze/expand and break the seal, allowing water back into the stringers.